I'm I wrong for wanting to change him?

I just was reconnected 4 months ago with this guy I've known since the 6th grade. He is the sweetest most thoughtful guy I have ever talked to and I am remotely attracted to him. He wants to become a couple and I am so close to saying yes, but there is one problem. I'm attracted to his face and personality, but the body is another story. He's not fat but he used to be, just a little chub on the chest and stomach left over, something he could get rid of in like 6 weeks and he's not very muscular. My question is, would it be wrong for me to sway him into maybe joining a sports team or getting a gym membership? He so sweet and he'd probably do what ever I ask, but I don't want to come off as controlling of selfish. I just would feel a lot more attracted to him if he gained muscle. I don't know why people act like physical attraction isn't important for a good relationship, it is. So sway him or not??